Question

A spectrograph is used to determine what characteristic of a star?

Answer 1

Mainly the Composition of a Star.

Explanation:

A Spectrograph is used with telescopes to obtain Spectrum of the Stars and other Objects in Space.

With the help of the Spectrum obtained we can determine what a Star is made of( different elements have different Absorption lines at particular wavelengths), it's temperature range(Whether It's Spectrum peaks in Blue or Red) and the Red-Shift of the Star.

With this Red-Shift we can determine how far away the object is and how fast it is receding away from us as the Hubble Law suggests. We usually use the Spectrum of the Sun as a reference to determine the Red-Shifts of the Objects.

omposition of a Star.